Atomization sources, such as flames, may be used for a variety of applications, such as welding, chemical analysis and the like. In some instances, flames used in chemical analyses are not hot enough to vaporize the entire liquid sample that is injected into the flame. In addition, introduction of a liquid sample may result in zonal temperatures that may provide mixed results.
Another approach to atomization is to use a plasma source. Plasmas have been used in many technological areas including chemical analysis. Plasmas are electrically conducting gaseous mixtures containing large concentrations of cations and electrons. The temperature of a plasma may be as high as around 6,000-10,000 Kelvin, depending on the region of the plasma, whereas the temperature of a flame is often about 1400-1900 Kelvin, depending on the region of the flame. Due to the higher temperatures of the plasma, more rapid vaporization, atomization and/or ionization of chemical species may be achieved.
Use of plasmas may have several drawbacks in certain applications. Viewing optical emissions from chemical species in the plasma may be hindered by a high background signal from the plasma. Also, in some circumstances, plasma generation may require high total flow rates of argon (e.g., about 11-17 L/min) to create the plasma, including a flow rate of about 5-15 L/min of argon to isolate the plasma thermally. In addition, injection of aqueous samples into a plasma may result in a decrease in plasma temperature due to evaporation of solvent, i.e., a decrease in temperature due to desolvation. This temperature reduction may reduce the efficiency of atomization and ionization of chemical species in some contexts.
Higher powers have been used in plasmas to attempt to lower the detection limits for certain species, such as hard-to-ionize species like arsenic, cadmium, selenium and lead, but increasing the power also results in an increase in the background signal from the plasma.
Certain aspects and examples of the present technology alleviate some of the above concerns with previous atomization sources. For example, a boost device is shown here as a way to assist other atomization sources, such as flames, plasmas, arcs and sparks. Certain of these embodiments may enhance atomization efficiency, ionization efficiency, decrease background noise and/or increase emission signals from atomized and ionized species.